Merge pull request #28 from AntonRutkevich/parametrize-prometheus-metric

Add ability to parametrize prometheus metric name

templates/prometheus

@@ -6,6 +6,7 @@ import (
 )
 
 {{ $decorator := (or .Vars.DecoratorName (printf "%sWithPrometheus" .Interface.Name)) }}
+{{ $metric_name := (or .Vars.MetricName (printf "%s_duration_seconds" (down .Interface.Name))) }}
 
 // {{$decorator}} implements {{.Interface.Type}} interface with all methods wrapped
 // with Prometheus metrics
@@ -16,8 +17,8 @@ type {{$decorator}} struct {
 
 var {{down .Interface.Name}}DurationSummaryVec = promauto.NewSummaryVec(
   prometheus.SummaryOpts{
-    Name: "{{down .Interface.Name}}_duration_seconds",
-    Help: "{{down .Interface.Name}} runtime duration and result",
+    Name: "{{$metric_name}}",
+    Help: "{{ down .Interface.Name }} runtime duration and result",
     MaxAge: time.Minute,
     Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
   },

templates_tests/interface.go

@@ -9,3 +9,11 @@ type TestInterface interface {
 	NoParamsOrResults()
 	Channels(chA chan bool, chB chan<- bool, chanC <-chan bool)
 }
+
+// AnotherTestInterface is used to test templates where TestInterface was already used
+type AnotherTestInterface interface {
+	F(ctx context.Context, a1 string, a2 ...string) (result1, result2 string, err error)
+	NoError(string) string
+	NoParamsOrResults()
+	Channels(chA chan bool, chB chan<- bool, chanC <-chan bool)
+}

templates_tests/interface_with_prometheus_metric_name.go

@@ -0,0 +1,85 @@
+package templatestests
+
+// DO NOT EDIT!
+// This code is generated with http://github.com/hexdigest/gowrap tool
+// using ../templates/prometheus template
+
+//go:generate gowrap gen -p github.com/hexdigest/gowrap/templates_tests -i AnotherTestInterface -t ../templates/prometheus -o interface_with_prometheus_metric_name.go -v MetricName=custom_metric_name_seconds
+
+import (
+	"context"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+// AnotherTestInterfaceWithPrometheus implements AnotherTestInterface interface with all methods wrapped
+// with Prometheus metrics
+type AnotherTestInterfaceWithPrometheus struct {
+	base         AnotherTestInterface
+	instanceName string
+}
+
+var anothertestinterfaceDurationSummaryVec = promauto.NewSummaryVec(
+	prometheus.SummaryOpts{
+		Name:       "custom_metric_name_seconds",
+		Help:       "anothertestinterface runtime duration and result",
+		MaxAge:     time.Minute,
+		Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+	},
+	[]string{"instance_name", "method", "result"})
+
+// NewAnotherTestInterfaceWithPrometheus returns an instance of the AnotherTestInterface decorated with prometheus summary metric
+func NewAnotherTestInterfaceWithPrometheus(base AnotherTestInterface, instanceName string) AnotherTestInterfaceWithPrometheus {
+	return AnotherTestInterfaceWithPrometheus{
+		base:         base,
+		instanceName: instanceName,
+	}
+}
+
+// Channels implements AnotherTestInterface
+func (_d AnotherTestInterfaceWithPrometheus) Channels(chA chan bool, chB chan<- bool, chanC <-chan bool) {
+	_since := time.Now()
+	defer func() {
+		result := "ok"
+		anothertestinterfaceDurationSummaryVec.WithLabelValues(_d.instanceName, "Channels", result).Observe(time.Since(_since).Seconds())
+	}()
+	_d.base.Channels(chA, chB, chanC)
+	return
+}
+
+// F implements AnotherTestInterface
+func (_d AnotherTestInterfaceWithPrometheus) F(ctx context.Context, a1 string, a2 ...string) (result1 string, result2 string, err error) {
+	_since := time.Now()
+	defer func() {
+		result := "ok"
+		if err != nil {
+			result = "error"
+		}
+
+		anothertestinterfaceDurationSummaryVec.WithLabelValues(_d.instanceName, "F", result).Observe(time.Since(_since).Seconds())
+	}()
+	return _d.base.F(ctx, a1, a2...)
+}
+
+// NoError implements AnotherTestInterface
+func (_d AnotherTestInterfaceWithPrometheus) NoError(s1 string) (s2 string) {
+	_since := time.Now()
+	defer func() {
+		result := "ok"
+		anothertestinterfaceDurationSummaryVec.WithLabelValues(_d.instanceName, "NoError", result).Observe(time.Since(_since).Seconds())
+	}()
+	return _d.base.NoError(s1)
+}
+
+// NoParamsOrResults implements AnotherTestInterface
+func (_d AnotherTestInterfaceWithPrometheus) NoParamsOrResults() {
+	_since := time.Now()
+	defer func() {
+		result := "ok"
+		anothertestinterfaceDurationSummaryVec.WithLabelValues(_d.instanceName, "NoParamsOrResults", result).Observe(time.Since(_since).Seconds())
+	}()
+	_d.base.NoParamsOrResults()
+	return
+}

templates_tests/interface_with_prometheus_metric_name_test.go

@@ -0,0 +1,33 @@
+package templatestests
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTestInterfaceWithPrometheusMetricName_F(t *testing.T) {
+	t.Run("no error", func(t *testing.T) {
+		impl := &testImpl{r1: "1", r2: "2"}
+
+		wrapped := NewAnotherTestInterfaceWithPrometheus(impl, "test")
+		r1, r2, err := wrapped.F(context.Background(), "a1", "a2")
+
+		assert.NoError(t, err)
+		assert.Equal(t, "1", r1)
+		assert.Equal(t, "2", r2)
+	})
+
+	t.Run("with error", func(t *testing.T) {
+		impl := &testImpl{r1: "1", r2: "2", err: errors.New("unexpected error")}
+
+		wrapped := NewAnotherTestInterfaceWithPrometheus(impl, "test")
+		r1, r2, err := wrapped.F(context.Background(), "a1", "a2")
+
+		assert.Error(t, err)
+		assert.Equal(t, "1", r1)
+		assert.Equal(t, "2", r2)
+	})
+}